Hydroponic growing enclosure and method for growing, harvesting, processing and distributing algae, related microrganisms and their by products

ABSTRACT

Systems and methods for hydroponically growing microorganisms within a self-contained air-supported structure, in which microorganisms are grown in an organic slurry, harvested, and processed to obtain and process and distribute molecules useful for biofuel or other purposes.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application is a Continuation of U.S. patent application Ser. No.11/840,533 filed Aug. 17, 2007 now U.S. Pat. No. 7,536,827 which in turnclaims benefit of U.S. Provisional Patent Application Ser. No.60/822,667 filed Aug. 17, 2006. the entire disclosure of both documentsis herein incorporated by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to a hydroponic growing system and amethod of growing, harvesting, processing and distributing algae orother microorganisms And their benefits, uses and by-products,including, but not limited to bio diesel, animal feed, fertilizer,pharmaceuticals and the like.

2. Description of the Related Art

Photosynthetic organisms, or more commonly plants, can produce virtuallyany substance man has need of. For many years plants have producedfoodstuffs, clothing materials, and other basics necessary for thesurvival of humankind. Recently, bioengineered plants have beendeveloped that produce other useful materials such as designedpharmaceuticals and chemical intermediates. Further, even the most basicof plants can be used to help remove carbon dioxide from the Earth'sair. This is an important benefit as increased levels of carbon dioxidefrom an industrial society are linked to global warming andenvironmental detriment.

One use of plants which has recently been of renewed interest is theirprovision of clean energy. While plant matter has been burned for fuelsince the early history of mankind, recently the use of plants as asource for variable combustable materials which can be used for motorfuel has seen increased interest. Nations around the world are beginningto recognize that emissions from motor fuels, particularly gasoline anddiesel fuel, are undesirable. Further, current materials which aregenerally petrochemicals refined from geologic deposits, are a limitedresource and fuels which can potentially supersede them are ofparticular scientific interest. The burning of many plant based productsis cleaner than the burning of petroleum products, resulting in improvedenvironmental conditions; and is a renewable source of fuel.

Currently the two most well known bio-fuels which are seeing a largeamount of press are ethanol, an alcohol generally made from sugarcane,rapeseed, corn, or other plant matter which is used as an additive togasoline; and biodiesel, which is a mixture of diesel fuel with variousforms of plant oil (generally soybean or rapeseed oil). Biodiesel mayalso comprise pure vegetable oils or vegetable oil blends, in some casesburning cooking oils. In the current world, both ethanol and plant oilbased materials are used as additives to existing petrochemicals toprovide for mixtures due to both price and consumer interest in thesematerials. Further, as current motor vehicles are not necessarilyoptimized for operation on these fuels, mixtures often produce betterresultant fuel economy (where fuel is broadly defined to include thepetrochemical and additive blend) than burning the additive alone.

Gasoline engines can also have trouble with the lighter ethanolmaterial. In the future it is expected that engines will be built whichare designed to run on these types of fuels exclusively and obtainbetter efficiency than today's engines which are not necessarilyoptimized for use with these types of fuels. Even today, however, desireto eliminate dependence on oil is making these types of products moreand more economically sound. With the development of the carbon creditmarket, whereby environmentally friendly means of generating energy alsogenerate credits with a monetary market value which can be sold to lessenvironmentally friendly enterprises, advances from oil to biofuels mayalso be profitable.

While these fuels are already making a relatively significant change inthe way that the human population thinks about motor fuel, both fuelshave one significant shortfall. While the underlying source of the fuelscan be grown in a regular cycle, both fuels are currently based onrelatively complex plant forms (such as rapeseed, corn, and soybeans).While these crops are grown in huge numbers by agriculture around theworld and are well understood, the plants still take a significantamount of time to grow which necessarily limits crop size. Further, theprocesses to turn these devices into fuel often only utilize the seedkernel or other product of the plant and are unable to utilize all theplant structure in fuel production. While the discarded components maybe useful elsewhere, demand for fuel can lead to an excess of plantproducts not useful in its production.

While oils and alcohols to be used can be derived from virtually anytype of plant, the current use of more complex life forms createsunnecessary waste and problems from fertilizer runoff and complicatedmarkets. In particular, most foodstuffs, animal feeds, and raw materialsformed by plants and used by humans are from relatively complexorganisms. While much of the plant waste is used as animal feed orbedding, or may be left on the field as a form of fertilizer, this meansthat humans get very little value from a plant compared to the actualbiomass of the plant produced.

This shortfall results in two significant concerns in the use of thesematerials as motors fuels. In the first instance, the supply of rawmaterials is cyclical over a relatively long period. Often only one ortwo harvests of the raw material can be made every year. This results inthe need to plan ahead for demand needs. Further, because the plantgrowing cycle is necessarily dependent on the weather and various otherrelated factors outside of the growers' control, the cyclical pattern isalso somewhat unpredictable. In this way the cost of the fuels canbecome unexpected and can experience fluctuations which are undesirableto the eventual consumer.

Because of these types of problems, it is expected that, in the future,photosynthetic microorganisms such as algae, Cyanobacteria, plankton,and similar lifeforms will play a larger role than higher plants inphotosynthetic carbon dioxide fixation because they have higherphotosynthetic rates per unit biomass and, if optimized, can becultivated in a compact space.

The potential of algae, Cyanobacteria, and other similar microorganismsas a food staple in the human diet has been investigated over many yearsin several countries. In the US and Japan, algal biomass includingChlorella and Spirulina is produced commercially, primarily as healthfood and is available for human consumption through a relatively largenumber of outlets. Algae are also used in lagoons on farms to processlivestock waste and thereby lower amounts of pollutants, includingphosphorus and nitrogen, in ground-water.

Further, algae and other microorganisms can be used as a raw materialfor the production of oil or alcohol to be used as a motor fuel. Thehigh lipid content of many microalgae produces high natural omega-3content which can be useful for human consumption or in the productionof nutritional supplements as well as making it particularly valuable asa source of oil for motor fuel. It is also believed that algae canproduce up to 60 percent of their weight in useful fuel molecules calledtriacylglycerols. It should be recognized that algae and othermicroorganisms can be used for a number of purposes and the system andmethods discussed herein can be used for the production of thesematerials for any purpose.

Production of algae under current standards, however, would be expectedto be unable to meet demand if algae products were used for motor fuelor otherwise became widespread. In particular, traditionally algae andCyanobacteria have been grown only in laboratory photobioreactors whichare not viable for commercial production, and in outdoor raceways, inopen lakes, and in oceans. While these later methods are effective atproducing algae for commercial use, these types of systems require vastamounts of space compared to the amount of algae they produce and arerelatively difficult to harvest and keep clear of contamination.Further, just like other crops, photosynthetic microorganisms producedin outdoor raceways are at the mercy of the weather and contamination.

Hydroponics is the art of growing plants without soil and has beenpracticed for many years. Hydroponic systems for growing flowers, fruit,and vegetables in a controlled environment and without use of soil hasbeen practiced in over 10 known applications over the last 40 years.Generally, controlled hydroponic systems for the production of complexplants such as commercial flowers or vegetables comprise a controlledenvironmental enclosure in which plants are germinated and grown ontrays. The enclosure is usually a conventional greenhouse. A structureis formed with a steel skeleton, the skeleton then being covered withpanes of transparent glass or plastic to allow sunshine onto the plantsto allow photosynthesis. Most of these applications also include sometype of air conditioning (whether heating or cooling) and distributionsystem, a water supply and irrigation system, and may also includeartificial light sources to enhance light available to the plants.

These types of traditional photobioreactors are simply not commerciallyviable for mass production of algae, Cyanobacteria, and othermicroorganisms. They are not cost effective in producing largequantities of high quality. Because the structures are simply tooexpensive to construct at sufficient size, and as opposed to morevaluable crops such as vegetables and flowers, algae simply does nothave a sufficiently high margin to justify such production.

Because no efficient large-scale photobioreactors had yet beenavailable, open cultivation ponds and clear tubes and tank systems havebeen used for almost all commercial algae production (generally for useas food additives). However, it is difficult to obtain high productivityin open ponds because the temperature and light intensity varythroughout the day and year and tube and tank systems are costly toconstruct and maintain. In addition, open ponds require a large surfacearea, and problems with contamination arise.

It is therefore desirable for a large-scale photobioreaction to beeconomically feasible for the purposes of mass-producing algae,Cyanobacteria, and other microorganisms from which biofuel may bederived.

SUMMARY

The following is a summary of the invention in order to provide a basicunderstanding of some aspects of the invention. This summary is notintended to identify key or critical elements of the invention or todelineate the scope of the invention. The sole purpose of this sectionis to present some concepts of the invention in a simplified form as aprelude to the more detailed description that is presented later.

Because of these and other problems in the art described herein, amongother things, is a system for hydroponically growing, harvesting,processing and distributing photosynthetic microorganisms and their byproducts comprising: a self-contained growing enclosure, furthercomprising: an air supported structure, further comprising a skeleton, amembrane placed over said skeleton in a manner designed to be permanent,and a grid system affixed to said skeleton; a control compartment,further comprising a plurality of storage tanks and controls for saidsystem, wherein at least a first storage tank of said plurality ofstorage tanks contains a liquid medium, at least a second storage tankof said plurality of storage tanks contains microorganisms, and at leasta third storage tank of said plurality of storage tanks acting as amixing tank within which said liquid medium is mixed with saidmicroorganisms in predetermined quantities to form a slurry; a pluralityof cradles capable of receiving said slurry through an inlet end, andpermitting harvest of said microorganisms through an outlet harvest end;wherein said plurality is vertically racked; and wherein said pluralitypermits said slurry to move from said inlet end to said outlet harvestend in a manner that permits growth of said microorganisms; a handlingsystem capable of conveying carbon dioxide and predetermined quantitiesof material stored within said storage tanks to at least one cradle ofsaid plurality of cradles; and means for distributing carbon dioxide toa section of said inlet end of at least one of said plurality ofcradles.

In an embodiment of the system said structure is maintained by amechanical operating system, comprising a fan, a heater, and a coolingelement and said means for distributing is a perforated tube presentalong said cradle's length and an air handling and conditioning system.

In an embodiment of the system said enclosure further comprises meansfor making available a continuous conditioned and filtered air flowacross all of said cradles.

In an embodiment the system further comprises a light source capable ofradiating light from under said cradles to said microorganisms. Suchlight source may comprise a tube structure enclosing a plurality oflight bulbs and affixed on said cradles' underside, and wherein saidunderside is translucent or transparent.

In an embodiment of the system said microorganisms are algae or bacteriaand said liquid medium comprises substances derived from an excess,including but not limited to a sewerage excess or a farming excess andwater.

In an embodiment of the system the movement of said slurry is aided bygravity. The membrane may be an outer membrane, and said structurefurther comprises an inner membrane.

In an embodiment, the system further comprises means for harvesting byfroth floating, flocculating, dissolved air floating, or centrifugingand means for processing by centrifuging or homogenizing.

In another embodiment of the system the controls automate said mixing ofsaid slurry, said receipt of said slurry, said movement of said slurry,operation of said handling system, operation of said means forharvesting, and operation of said means for processing.

There is also described herein, a method of providing beneficialby-products of photosynthetic microorganisms, the method comprising:having a self-contained growing enclosure, comprising an air supportedstructure further comprising a membrane; installing a racking system,comprising racked cradles, within said enclosure; mixing a predeterminedquantity of liquid medium from a first storage means with apredetermined quantity of said microorganisms from a second storagemeans to form a slurry; placing said slurry in a predetermined number ofsaid cradles at an inlet end of said cradles; distributing carbondioxide to said cradles; causing said slurry to flow from said inlet endto an outlet harvest end of said cradles in a manner that permitsmultiplication of said microorganisms; making available a continuousconditioned and filtered air flow across all of said cradles; harvestingsaid microorganisms at said outlet harvest end; and processing saidmicroorganisms to obtain molecules useful in fuel, wherein saidmicroorganisms are separated into oil and solids, and further processingsaid microorganisms for other by products including, but not limited tobio diesel, animal feed, fertilizer, pharmaceuticals and the like.

In an embodiment the method further comprises radiating light from undersaid cradles to said microorganisms, which may be algae or bacteria.

In an embodiment of the method, the placing or causing may aided bygravity, such as by positioning the cradles at about a 1 to 5 degreeangle.

In another embodiment of the method, the carbon dioxide is drawn from astorage means.

In another embodiment of the method, the making is performed by an airhandling and conditioning system.

In another embodiment of the method the liquid medium comprisessubstances derived from farming excess and water. The membrane may alsobe an outer membrane, and said structure further comprises an innermembrane, a skeleton, a grid system affixed to said skeleton and supportfor maintaining said structure further comprising a fan, a heater, and acooling element.

In a still further embodiment of the method, the distributing isperformed by a perforated tube present along said cradles' length, theharvesting comprises froth floating, flocculating, dissolved airfloating, or centrifuging, and the processing comprises centrifuging orhomogenizing.

In a still further embodiment of the method the mixing, placing,distributing, causing, making, harvesting, and processing arecontinuously repeated and may be automatically controlled.

There is also described herein a method of hydroponically growingphotosynthetic microorganisms comprising: deriving a liquid medium;storing said liquid medium in a first storage means; storingmicroorganisms in a second storage means; mixing a predeterminedquantity of said liquid medium from said first storage means with apredetermined quantity of said microorganisms from said second storagemeans to form a slurry, wherein said slurry is stored in a third storagemeans that is in fluid communication with said first storage means andsaid second storage means; storing carbon dioxide in a fourth storagemeans; having a self-contained growing enclosure, comprising a structurefurther comprising a membrane; installing a racking system, comprisingracked cradles, within said enclosure, wherein said racking system is influid communication with said third storage means, and said fourthstorage means; placing said slurry in a predetermined number of saidcradles at an inlet end of said cradles; distributing a predeterminedquantity of said carbon dioxide from said fourth storage means into saidcradles via said fluid communication; causing said slurry to flow fromsaid inlet end to an outlet harvest end of said cradles in a manner thatpermits multiplication of said microorganisms; making available acontinuous conditioned and filtered air flow across all of said cradles;conveying said microorganisms from said outlet harvest end to a meansfor harvesting; harvesting said microorganisms with said means forharvesting; and processing said microorganisms by separating saidmicroorganisms into oil and solids, and further processing saidmicroorganisms for other by products including, but not limited to biodiesel, animal feed, fertilizer, pharmaceuticals and the like.

In an embodiment of the method, the harvesting comprises froth floating,flocculating, dissolved air floating, or centrifuging and the processingcomprises centrifuging or homogenizing. In a further embodiment themethod further comprises transportation, distribution and conveyance ofcomponents or by products for further processing.

In an embodiment, the method further comprises radiating light fromunder said cradles to said microorganisms which may be algae orbacteria.

In another embodiment of the method the liquid medium comprisessubstances derived from an excess, including but not limited to asewerage or a farming excess and water.

In another embodiment of the method said steps of mixing, placing,distributing, causing, making, harvesting, processing and distributingare continuously repeated, may be automatically controlled, and may beperformed at co-located facilities and at distal locations.

In a still further embodiment, the structure is supported by frames,airbeams or another form of support, or may be a tension-supportedstructure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view of an embodiment of a hydroponicgrowing enclosure.

FIG. 2 is a floor plan of another embodiment of a hydroponic growingenclosure similar to that of FIG. 1.

FIG. 3 is a simplified sectional side view of the embodiment of FIG. 2along line 3-3.

FIG. 4 is a side elevational view of the enclosure of FIG. 1.

FIG. 5 is a simplified sectional view of the enclosure of FIG. 2 alongthe line 5-5.

FIG. 6 provides a side and front view of an air handling unit.

FIG. 7 is a perspective view of an embodiment of a cradle rackingsystem.

FIG. 8A is a sectional view of a first embodiment of a cradle rackingsystem. FIG. 8B is a sectional view of a second embodiment of a cradleracking system.

FIG. 9 is a perspective view of an alternative embodiment of a cradleracking system.

FIG. 10 is a sectional view showing an embodiment of a cradle withcarbon dioxide and light supplied.

FIG. 11 is a simplified sectional view along the line 11-11 of theenclosure of FIG. 2 showing the utility trench.

FIG. 12 is a simplified sectional view along line 12-12 of the enclosureof FIG. 2.

FIGS. 13A and 13B are partial circuit diagrams of an embodiment of anair handling and conditioning system.

FIG. 14 is another circuit diagram of an embodiment of an air handlingand conditioning system.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Throughout this disclosure, the microorganisms being described will bereferred to as algae. This is to provide for an exemplary organism. Aswould be understood by one of ordinary skill in the art, the discussionof growing algae can be applied, without undue experimentation, to thegrowing of Cyanobacteria or other similar microorganisms. Further, thesystems and methods discussed herein do not provide for any particulartype(s) of algae to be grown and harvested. This is because it isexpected that any desired algae(s) may be grown, harvested andprocessed, and by products distributed.

FIGS. 1 through 5 provide various views of a structure (101) and growingenclosure (100) which may be utilized in an embodiment of the invention,generally comprising five main components which relate to generalaspects of the operation of the enclosure (100) in growing of the algae.The primary component is a housing structure (101) which serves toisolate the algae and growth process from the external environment.

The second component is a control compartment including storage tanks(203) designed to contain a liquid medium which will serve as a growthmaterial for the algae. The liquid medium will generally include water,liquefied animal waste, and/or other fertilizers. The controlcompartment will also include control elements of the various devicesand the structure itself. It may also include various tanks for storingalgae prior to (205) and after (207) harvesting.

The third component is a handling system for conveying carbon dioxide,the liquid medium and a starting growth of algae in the form of spores,seeds or related structures from the storage tanks to a plurality ofcultivation and growing cradles (401). The handling system will comprisepipes, wiring, and similar components which are generally placed in acovered utility trench (301) in the base (103) of the structure (101).

The fourth component is the cradles (401) themselves. The cradles (401)serve to contain the liquid medium and algae and provide it with accessto light and air. The cradles (401) are generally arranged in agenerally racked form and are capable of holding the liquid medium.Generally the cradles (401) have an inlet end (409) for input of theliquid medium, algae, and distribution of carbon dioxide and an outletharvest end (411) where, once the algae has developed to theprerequisite mass they can be harvested.

The fifth component of the system comprises the harvesting, processing,conversion and distribution of the raw algae into the desired byproducts or substance such as biofuel which is then stored, distributedand further processed at the same or a distal location. In anembodiment, once it is grown, the algae will generally be removed fromthe building via gravity flow and may be mechanically separated from thegrowth medium by piping (501) the resulting algae to a centrifuge orsimilar device. Both the growth medium and the algae may then beprocessed in any manner known to one of ordinary skill in the art toproduce desired outputs.

In an embodiment, the enclosure (100) is used as part of a method ofhydroponically growing photosynthetic organisms within the enclosure(100) and independent of outside climatic conditions, said methodcomprising the steps of: mixing a predetermined quantity of liquidmedium from a storage means with a predetermined quantity ofphotosynthetic microorganisms such as algal spores or the like; placingthe resultant slurry in a predetermined number of transparent growingcradles (401) at an inlet end (409) of a racking system such as throughthe use of gravity, this placement may be by weight or other manner;radiating light from under the cradles (401) to the microorganisms;circulating a continuous conditioned and filtered air flow across all ofsaid cradles (401) supported in said racking system from said inlet end(409) to an outlet harvest end (411); and distributing carbon dioxidegenerated or from a storage means (209) to said cradles. This may berepeated in a continuous fashion to provide for a constant growth ofmicroorganisms.

The growing enclosure (100) generally comprises a liquid medium storagetank (203) located as part of a control compartment section of theenclosure (100) and preferably isolated from a growing and harvestcompartment section. The liquid medium will comprise some mixture ofwater and nutrients which may be provided organically or synthetically.In an embodiment, the liquid medium comprises some form of black or graywater and may include human or animal waste. In an embodiment, theliquid medium is liquefied sewerage, animal manure, forest or millresiduals, and/or spoiled animal feed, such as is provided from theoutput of an anaerobic digester or related structure. Such a liquidmedium accomplishes the goal of productively using excess such assewerage or farming wastes like excess feed and fertilizer.

Pipes (307) convey the liquid medium from a storage tank (203) to amixing tank (205). Here the liquid medium is mixed with algae, algalspores or related materials to produce a slurry suitable for algalgrowth. The slurry is then provided by piping (303) to the input end(409) of a cradle (401). The cradles (401) are generally provided in aracking system in the growing and harvest compartment to support aplurality of layers for cultivating the algae in horizontallyspaced-apart arrangement. Each cradle in the racking system has an inletend (409) where the liquid medium/algae mix is input and extends along alength where the algae is growing until reaching a terminal end (411)where algae is harvested.

In alternative or single embodiments, each, some, or all of the mixingtank (205), pipes (307), and liquid medium storage tank (203) areco-located with the enclosure. In further embodiments, these components(205, 307, 203) may be located within the enclosure (100), on anadjunct, or as part of a wing thereof. In a further embodiment, thetanks (203, 205) and pipes (307) may be located in the growing andharvest compartment of the enclosure (100). Such co-located embodimentsenable the processes disclosed herein to be conducted efficiently,without the costs and risks of transport between facilities, but are byno means required and in alternative embodiments, such facilities may belocated at disparate locations. Such risks of disparate location mayinclude damage to the microorganisms, contamination of transportedsubstances, miscommunication between origin and destination facilities,or inevitable delays in transport (i.e., due to weather) that interruptthe processes disclosed herein.

The cradles (401) preferably are placed in close proximity to aperforated tube (410) which runs the length of each cradle (401) and, inan embodiment, may protrude (412) into the internal volume of the cradle(401). The tube (410) serves as a gas distribution system distributingcarbon dioxide along the length of the cradle (401). Light units (700)are provided in an embodiment in conjunction with the cradle (401). Thelight units are preferably dimensioned to provide light over all of theliquid growing medium and to the algae. An air handling and conditioningsystem (601) having directional air outlet means is provided forrecirculating the carbon dioxide gas and for circulating air in theenclosure (100). A water supply conduit (305) may also be supplied tothe enclosure (100) to connect with an external pressurized water supplysource for maintenance.

In the depicted embodiment, the enclosure (100) is preferably an airsupported structure (101) a frame-supported structure, or a structurewhich can be used to maintain the environment at desired levels,fabricated from vinyl coated polyester, with an inner liner of aninsulating material, whereby the enclosure can be temperature-controlledto facilitate growth of photosynthetic organisms independently ofoutside climatic conditions. The structure (101) may be assembled onsite by the use of conventional tools.

As the structure (101) is air supported, it can be of virtually any sizeand it is generally preferred that the structure (101) be of significantsize so as to facilitate economies of scale. In an embodiment, it may be10′ by 10′ by 30′ long. An air supported structure (101) has a number ofadvantages in this application due to its ability to support its ownweight regardless of resulting size or shape. It is preferred thatmembrane (111) of the structure (101) be light permeable, at least inthe wavelengths of light used by the algae for photosynthesis. It isalso preferred that membrane (111) be resistant to ultraviolet lightdegradation.

It is preferred that the self-contained hydroponic growing structure(101) include an insulated fabric membrane (111) forming its principlestructure to provide for outdoor use and continuous operation underoutside climatic conditions ranging from about −40 degrees Fahrenheit toat least +100 degrees Fahrenheit without significant attention to itsinternal temperature. In an embodiment, the membrane (111) is white, maybe translucent, and made of a variety of architectural material,including but not limited to, DACRON™. It is preferred that the membranebe fire resistant in accordance with applicable regulations. In anembodiment, the membrane (111) weighs between about 28 and about 30ounces per square yard.

To provide temperature control in an embodiment, a vinyl-coated,translucent, polyester second layer (not shown) may be constructed ontothe outer membrane (111), creating a dead-air space of generally 6-12″.In an embodiment, this second layer may weigh 14 ounces per yard, andmay also be fire resistant. This results in a minimum cost of heatingand/or air conditioning the structure and provides for installingfiberglass or other insulating materials, if desired. The second layerand air space may also serve as an acoustical barriers. In anembodiment, the second layer is attached using a perpendicular “tab”detail to attach the inner and outer fabric allowing for 100%insulation, In such an arrangement, when the inner and outer fabric meetthere are generally no condensation problems or interruption in thedead, insulated air space.

In an embodiment, the structure (101) is temporary. It may be formedfrom a skeleton made of synthetic materials, supported by air, aluminum,steel or other frames, or any combination thereof. In a furtherembodiment, the skeleton comprises a plurality of airbeams, which may beformed as is known in the art by covering an air bladder withthree-dimensional woven fabric, or by any equivalent means. In analternative embodiment, the skeleton comprises a tension-supportedstructure made of cables. Any form of skeleton which provides a sturdy,relatively temporary structure is contemplated. The air structuregenerally develops its structural integrity from an internal pressureprovided by an air handling unit and/or air rotation unit (601), whichreplaces natural air loss throughout the structure (101). The structure(101) is anchored to a concrete grade base (103), or directly to theearth via earth anchors. The anchors can be permanent, temporary or aseasonal installation.

On the skeleton is placed the fabric membrane (111) generally comprisingof a vinyl-coated polyester weave, which is available in a number oftranslucent or transparent colors. It is preferred that the membrane(111) be capable of transmitting light in a wavelength used forphotosynthesis by the organisms in the enclosure (100). However, naturallight is not required and photosynthesis can occur by entireillumination from artificial light. Custom fabrics, such as camouflagefor military applications, are also available.

The membrane (111) may be sewn together, heat sealed, ultrasonicallywelded, adhered or otherwise connected and held together. It is,however, preferred that membrane components be connected by electronicradio frequency (RF) welding which develops seam construction equal tothe fabric or material strength. This generally increases the life ofthe structure (101), prevents undesirable air loss, and eliminatescostly maintenance and repair. Openings for human access doors (113) and(117), vehicle airlocks (115), blowers, heaters or air conditioning areplaced in the structure in a preferably tension-free arrangement.

The structure (101), in an embodiment, is further provided with a gridsystem (121) which prevents movement of the structure (101) in highwinds and decreases stress on the membrane (111), increasing safetyfactors and extending the life and usability of the structure (101). Inan embodiment, the grid system (121) Comprises vinyl-coated, galvanized,cable which is non-abrasive and designed to exceed the industry's basiccable systems safety factors, providing the structure (101) withperformance to equal, or exceed, that required by local structuralrequirements.

In an embodiment, the enclosure (100) is maintained by a mechanicaloperating system which may comprise a combination of speciallymanufactured fans, heat exchanger and related burner, cooling coils andcondensing unit, operating controls and many other accessories andoptions, including emergency and back-up generators and blowers.

Entrance into and out of the structure (101) may be through any numberof door's (113), (115) and (117). Generally these doors (113), (115) and(117) will be chosen to provide for a relative air seal so that there isminimum loss of air from inside the enclosure (100). The doors (113),(115), and (117) may comprise any type of door including air lock doubledoors (117) or revolving doors (113) and may be sized and shaped toaccommodate various types of traffic including vehicular airlocks (115)to provide access for forklifts or full-length tractor-trailers.Revolving doors (113), personal airlocks (117), and emergency exit doors(119) for entering and exiting under all conditions can be provided forhuman personnel.

The structure (101) will generally be clamped down, in most cases to aconcrete foundation (103) that is designed to take the structure (101).Alternatively, the structure may have earth anchors if designed fortemporary use or smaller size.

The enclosure (100) includes a control compartment section generallyexternal to the structure. The control compartment section may house twohopper tanks (203) which are fed liquid medium by means of pipes. Thepipes will generally connect to a co-located source of the medium, ormay alternatively be used to pipe in liquid medium from a remotelocation, or to unload trucks, rail cars, or other vehicles transportingthe liquid medium. There is also included a tank holding thephotosynthetic organisms (205) spores or seeds which are to beintroduced to the liquid medium as needed when provided to the cradles(401). The control compartment may also house a water tank (not shown)which is connected by suitable piping (305) to various components of thesystem in the event water is needed. A heater (not shown) may beprovided to maintain the temperature of the liquid medium during coldclimatic conditions outside the structure (101).

In an embodiment, a central system serves the self-contained hydroponicgrowing enclosure wherein the water feed system, as well as the airhandling system and carbon dioxide system, are automatically controlledeliminating the need for human workers to perform routine tasks.

In an embodiment, the enclosure (100) utilizes growing surfacescomprising cradles (401). The cradles (401) will generally be open air,having a troughlike structure, but alternatively may be enclosed. In thedepicted embodiment of FIGS. 7 and 8, the cradles (401) are formed intoa racking system which comprises a plurality of vertical spaced apartframe members (403), support members (405) secured to said verticalframe members for securing plastic cradles (401), the support membersbeing inclined downward from said inlet end to said outlet harvest endfor gravity feed of cradles (401) supported on the racks, stiffeningmembers (407) for improved strength of the racks, and the cradles (401)themselves. The racks may hold a single row of cradles (401), as in FIG.8A, or multiple rows, an embodiment of which is depicted in FIG. 8B.

The support members (405) may be strings or supportive netting extendingbeneath and along the width of the cradle (401); fasteners on eitherside of the cradle (401), such as clamps, screws, or adhesive; areceptive trough into which the cradle (401) nests; or any other meansknown in the art.

The vertical stacking of the cradles (401) allows for a large volume inwhich to grow the microorganisms, without requiring a large footprintfor the enclosure (100). The extent of vertical stacking is limited onlyby the desired height of the enclosure (100), as slurry introduction andharvesting can be conducted regardless of the cradle's (401) height, andthere are no structural limitations on the racking system's height. Dueto the translucence of the membrane (111) forming the “walls” of theenclosure (100), cradles (401) lower on the racking system still receiveadequate light for the microorganisms in those cradles (401) tophotosynthesize. In embodiments in which light sources are fixed to theunderside of the cradles (401), cradles (401) lower on the rackingsystem have their light supplemented in the event higher cradles (401)cast shadows over those lower cradles (401).

FIG. 9 illustrates an embodiment of the downward slope of the cradles(401). The downward angle slopes from the inlet end (409) to the outletharvest end (411) at preferably about a 1 to 5 degree angle, morepreferably a 2 degree angle. This provides for ease of harvesting bygravity as the slurry is pushed from the inlet end (409) for reloadingwith fresh liquid medium and algae from the mixing tank (205).

In an alternative embodiment, shown in FIG. 9, cradles (401) within arack may be in fluid communication, through connective piping,alternating downward slopes, or any other means. Such an embodiment maybe useful where algae need a longer time to grow than is afforded by thetime it takes the slurry to travel down one cradle (401); it may also bepreferred where an enclosure's (100) width is limited. In such anembodiment, a cradle's (401) input end (409) is defined by slurry entry,and the output harvest end is defined by slurry exit, even thoughharvesting may not occur upon that exit.

As shown in the depicted embodiment, the racking system is secured overa drainage floor, which is inclined to channel water to a dischargeconduit to direct any spillage toward a drain or otherwise out of thestructure. As previously described, there may be water tanks (not shown)constituting a reservoir means for supplying water for maintenance.

The liquid medium and algae slurry is fed into the cradles (401) at aninput end (409). Generally, a feeding will occur to keep the amount ofslurry in the cradles (401) relatively constant. The gravity feed mayalso serve to move various items outside the cradles (401). As shown inFIG. 11, the base (103) of the structure (101) may include a trough(301) covered by a cover (311) and including various pipes and conduitsas indicated.

The gravity racking system can be particularly useful as it can resultin what amounts to a steady flow of algae and medium from the input end(409) to the harvest end (411) of the cradle (401). This can provide fordisplacing of the algae on a regular basis and in a manner which is easyto use for loading or unloading. In an embodiment, the algae effectivelylives its growth cycle as it passes down the length of the cradle (401).As the slurry enters the cradle (401) gravity causes the cradle to fill.During the growing cycle, the algae starts to grow throughout the slurryin the cradle (401). When the algae is ready to be harvested, a valve orsimilar device at the harvesting end (411) is opened and gravity causesthe algae and remaining liquid medium to exit the cradle (401) generallyinto outlet piping (307). It also begins to slowly be moved down thecradle (401) due to the force of gravity. This movement meets thealgae's need for some turbulence and diffusion of nutrients. As thealgae grows and increases its total mass, it slowly approaches theharvesting end (411). Eventually, the algal growth reaches the terminalend. This may be because the growth has reached a pre-selected mass orbecause a certain amount of time has passed.

At the final terminal end (411) the slurry is removed from the cradle(401) by any known harvesting means. The algae mixture is then piped out(307) of the structure and the algae is generally separated from theremaining liquid medium. In an embodiment, froth flotation separatesalgae from the medium by adjusting pH and bubbling air through a columnto create a froth of algae that accumulates above liquid level. Inanother embodiment, flocculation causes small particles to join togetherto form larger particles which can be more easily filtered using lesscostly equipment. Further embodiments provide a continuous flocculationeffect without the use of chemicals or additives. In another embodiment,dissolved air flotation separates algae from the medium using featuresof both froth flotation and flocculation. Alum may be used to flocculatean algae/air mixture, with fine bubbles supplied by air. Finally, inanother embodiment, centrifugation separates algae from the medium. Thiscauses the algae to settle to the bottom of the vessel. The liquidmedium is disposed of in any understood fashion, or may be recycled intothe cradles (401) if it is still sufficient for algae growth. The algaeis provided to a processing system to be processed into desired byproducts or materials. In an embodiment, a percentage of algae mayremain in each top cradle (401) to seed the next algae population.

In an embodiment, this processing system first separates the slurry intoalgae and water. A homogenizer as known in the art, which may be sonic,may then be used to rupture the cells. Algae components may then beseparated from liquid by centrifuge. In an alternative embodiment, thealgae slurry is first homogenized and then centrifuged to separate oil,water, and a high-protein algae paste. Water from any method may bereturned to the holding tank (not shown). These processes may take placeat the enclosure site or at a remote location. The algae components arethen used to derive molecules useful in biofuel, in a manner known inthe art or yet to be discovered.

In an embodiment, light units (700) are placed in conjunction with thecradles (401) to provide for increased photosynthesis of the algae cropwhile it is in the cradle (401). The light may be used in place of, orin addition to, solar light made available to the algae. In oneembodiment as depicted in FIGS. 8 and 10, the lights are placed on theundersides of the cradles (401) which are constructed of a translucentor transparent material to allow the light to be provided directly toeach of the cradles (401) from the underside. Placing lighting on theunderside of the cradle (401) can provide a number of advantages. Mostimportantly, the lighting can serve to provide light to a greatersurface area of the liquid medium than sunlight can provide alone. Thiscan allow for greater algal growth within the same volume of liquidmedium. Providing artificial lighting to the algae can also supplementnatural lighting by providing a greater intensity of useful wavelengthsand/or by providing lighting in a constant fashion, that is, theartificial lighting can continue to provide light to the algae even whennatural sunlight is not available, shortening the total required timefor growth.

In an embodiment and as shown in FIGS. 8 and 10, the light arrangements(700) comprise light bulbs (701) arranged in strips wherein the lightstrips are each comprised of a tube structure, the housing being awaterproof tube structure (703) disposed along a horizontal cradle, saidtube structure provides an even spectrum of light to said cradles (401).The light bulbs used may be of any type including filaments, arcs, LightEmitting Diodes (LEDs), Organic Light Emitting Diodes (OLEDs),fluorescent tubes, or other light structures.

As shown in FIG. 6, an air handling and conditioning system (601),including a mixing box section in an embodiment, circulates a continuousconditioned and filtered air flow across all of the trays supported inthe racking system. This both provides a source of carbon dioxide andclimate control, and can also serve to maintain the enclosure's (100)integrity. It is believed that temperature is particularly limiting onthe growth of cultured algae, and so is regulated in an embodiment.

FIGS. 13 and 14 provide embodiments of circuit diagrams associated withthe air handling and conditioning system (601). FIG. 13 shows anembodiment of control over the heating system, while FIG. 14 shows anembodiment of control over the power running the air handling andconditioning system.

With reference to the air handling and conditioning system for thehydroponic production of photosynthetic organisms: this system mayincorporate an air conditioning package capable of operation withseasonal outside temperature variations from −40 degrees Fahrenheit toat least +100 degrees Fahrenheit. The flesh air intake through theintake is generally a minimum of 10% of the system total air supplyquantity at all times during the year. The outside air compensates thesystem on a year-round basis and maximum economy is achieved by usingmore than minimum outdoor air for atmospheric cooling when outsideconditions permit, i.e., during marginal or in-between seasonalconditions allowing for consideration for maximizing algae growth. Whenthe air handling and conditioning system (601) is energized, a supplyfan and exhaust fan start operating. A changeover thermostat selectseither the summer or winter compensation mode according to outdoortemperature. At no-load condition, this schedule will change overautomatically.

On the winter compensation schedule, an electronic control panelcontrols the space temperature by coordinating signals from the internalspace thermostat discharge thermostat and an outdoor thermostat. Anelectric heating coil is also preferably provided with a step controller(not shown) whereby to sequence the electric heating coils depending onair temperature requirements. Outdoor and return air louvers may alsocontrolled. The cooling coils are controlled by a valve, depending onspace temperature requirements.

It is pointed out that an outside air thermostat may be adjustableeither to overcome system offset or elevate the space temperature withinthe enclosure as the outside temperature falls. The electronic controlpanel may program signals from the humidistat to control humidificationlevels in the space.

In the summer compensation mode, the electronic panel controls the spacetemperature by coordinating signals from the space thermostat andoutdoor thermostat to operate the cooling valve and cooling coil bypassdampers for cooling the outdoor and return air, for ventilating, orelectric heating element sequencing for heating depending on interiorspace temperature. The outdoor air thermostat causes the spacetemperature to elevate as the outside air temperature rises. When theoutside air is too warm, the outside air thermostat will return theoutdoor air damper to its minimum position (as established by a minimumposition switch) to eliminate outside excess fresh air and provideeconomical operation of the refrigeration equipment.

Under normal operation, the outdoor air damper motor positions thedampers at their minimum position except when outside air is used foratmospheric cooling. A thermostat provides signals concerning the returnair temperature in the mixing box section. The motor controls thedampers and these dampers are adjusted so that they do not completelyclose thereby preventing the cooling coils from frosting the dampers. Asherein shown, the exhaust air is also controlled by dampers, which arecontrolled by a motor, which connects to the electronic control panel.Although not shown, the electronic control panel is preferably a fullyautomated, computer-controlled panel and, with its sensor system, iscapable of operating the air conditioning system fully automatically.The electronic control panel can also be integrated in a centralprocessing unit (CPU) as understood by those of ordinary skill in theart whereby all working aspects of the hydroponic growing system arefully integrated. The CPU can also provide for system monitoring andadjustments through a computer located elsewhere.

In another embodiment, the air handling system (601) is a central systemsupplying pressurized air exiting said air outlet, and a return airoutlet for conditioning and recalculating said return air.

As discussed above, in an embodiment, there is also provided a waterholding tank capable of supplying temperature-adjusted water directly tothe header pipe for irrigation of the cradles (401) if needed. The watertank is preferably designed for loading through bottom inlets. The tanksare also designed for easy washdown and bottom draining. The airconditioning delivers a constant air flow substantially evenly acrosseach layer of the multi-layered growing cradles positioned in theracking system to provide carbon dioxide and temperature control. Carbondioxide may be provided as simply part of temperature controlled air ormay be supplied at an increased rate, as desired. In an embodiment,waste carbon dioxide is piped into the air handling unit to be supplied.

The hydroponic growing enclosure (100) and method of the presentinvention generally serves to produce an abundance of photosyntheticorganisms, particularly algaes, which are generally free fromimpurities. Further, the various apparatuses and process used aregenerally designed for low maintenance and minimum operational manpowerwhile also growing the algae in controlled conditions. Further, in anembodiment, the enclosure and method can provide for algae, which iscommercially valuable, from various waste products including carbondioxide from industrial process, sewerage and liquefied animal waste.

In an embodiment, the structure (101) and related components aredesigned for simple set up and tear down, being generally modular andproviding for a simple connection of structural and operating equipmentmodules. The system can be field-serviced by on-site personnel forroutine items or transported, in a trailer, for relocation or majorrepair. This allows for seasonal consumption or growing based on variousdemand factors. Further, as algae can generally be grown in only a fewdays, demand spikes for algae products can be fairly quickly compensatedfor by simply increasing algae output if additional capacity isavailable.

The enclosure and related structures are generally set up to operatefrom standard power lines depending on site conditions. In a preferredembodiment, the enclosure and process operates on a 220/110 volt servicewith back-up diesel generation on site. The main control panel locatedin the control room houses a set programmed chip which uses a sensornetwork to relay information to modular programmable controls located inthe unit. These controllers can manually override any of the operatingsystems or be reset to auto pilot. The main control panel is equippedwith communication ports for site and remote data downloading. Thestructure (101) may also be networked with other similar structures toallow making the enclosure (100) to operate together.

While the invention has been disclosed in conjunction with a descriptionof certain embodiments, including those that are currently believed tobe the preferred embodiments, the detailed description is intended to beillustrative and should not be understood to limit the scope of thepresent disclosure. As would be understood by one of ordinary skill inthe art, embodiments other than those described in detail herein areencompassed by the present invention. Modifications and variations ofthe described embodiments may be made without departing from the spiritand scope of the invention.

1. A system for hydroponically growing photosynthetic microorganismscomprising: a climate controlled air-supported structure including atranslucent membrane; a plurality of open cradles placed generallyhorizontally within said structure; wherein said plurality is capable ofreceiving a slurry comprising microorganisms in a liquid medium throughan inlet end, and permitting harvest of said microorganisms through anoutlet harvest end; and and wherein each of said cradles in saidplurality has a downward slope to permit said slurry to move from saidinlet end to said outlet harvest end in a manner that permits growth ofsaid microorganisms.
 2. The system of claim 1 wherein carbon dioxide isdistributed to at least one of said plurality of cradles within saidstructure.
 3. The system of claim 1 further comprising a light sourcecapable of radiating light from under said cradles to saidmicroorganisms.
 4. The system of claim 1 wherein said microorganisms arealgae.
 5. The system of claim 4 wherein said light source comprises atube structure enclosing a plurality of light bulbs and affixed on saidcradles' underside, and wherein said underside is translucent ortransparent.
 6. The system of claim 1 wherein said microorganisms arebacteria.
 7. The system of claim 1 wherein said liquid medium comprisessubstances derived from farming excess, and water.
 8. The system ofclaim 1 wherein said translucent membrane is an outer membrane, and saidstructure further comprises an inner membrane.
 9. The system of claim 1wherein each of said cradles has a downward slope of between about 1 andabout 5 degrees.
 10. A system for farming photosynthetic microorganismscomprising: means for storing a liquid medium; storing microorganisms ina second storage means; means for mixing a predetermined quantity ofsaid liquid medium with a predetermined quantity of microorganisms toform a slurry; a self-contained growing enclosure, comprising: astructure including a translucent membrane; a racking system, comprisinga plurality of racked, generally horizontal, open cradles, within saidenclosure; means for controlling temperature within said enclosure;means for directing said slurry into of said cradles at an inlet end ofsaid cradles; means for distributing a predetermined quantity of carbondioxide into said cradles; means for permitting multiplication of saidmicroorganisms; means for providing e a continuous conditioned andfiltered air flow across all of said cradles; means for harvesting saidmicroorganisms.
 11. The system of claim 10 wherein said means forharvesting utilizes froth floating, flocculating, dissolved airfloating, or centrifuging.
 12. The system of claim 10 said means forpermitting multiplication comprises means for radiating light from undersaid cradles to said microorganisms.
 13. The system of claim 10 whereinsaid microorganisms are algae.
 14. The method of claim 10 wherein saidmicroorganisms are bacteria.
 15. The system of claim 10 wherein saidliquid medium comprises substances derived from farming excess andwater.
 16. The system of claim 10 wherein said system is automated. 17.The system of claim 10 wherein said structure is supported by airbeams.18. The system of claim 10 wherein said structure is supported by airpressure.
 19. The system of claim 10 wherein said structure istension-supported.
 20. The system of claim 10 wherein each of saidcradles has a downward slope of between about 1 and about 5 degrees.